Anti-reflection film and image display device

ABSTRACT

An anti-reflection film, having a low-refractive-index layer formed by hardening a composition, the composition containing a polysiloxane compound having a reactive organic functional group represented by formula 1, and a perfluoroolefin copolymer: 
                 
 
wherein R 1 , R 2 , R 3  and R 4  each are a substituent having 1 to 20 carbon atoms; R 1 s, R 2 s, R 3 s or R 4 s each are the same or different; at least one of R 1 , R 3  and R 4  is the reactive organic functional group; x is an integer of 1≦x≦4; y is an integer of 10≦y≦500; z is an integer of 0≦z≦500; and the polysiloxane compound may be a random or block copolymer.

FIELD OF THE INVENTION

The present invention relates to an anti-reflection film, and a displaydevice (particularly a liquid crystal display device) provided with thesame.

BACKGROUND OF THE INVENTION

In image display devices, such as a cathode-ray tube display device(CRT), a plasma display panel (PDP), and a liquid crystal display device(LCD), anti-reflection films are generally provided on the outer surfaceof a display, so that reflectance can be reduced, using the principle ofoptical interference in order to prohibit reduction in contrast owing toreflection of external (ambient) light, and also not to mirror an imageof a surrounding from being seen on the display surface.

Such an anti-reflection film can be prepared by forming alow-refractive-index layer having a proper thickness, on ahigh-refractive-index layer. The material of the low refractive indexlayer is preferably as low as possible in refractive index, from theviewpoint of anti-reflection performance. In addition, high resistanceto abrasion (scratch) is demanded, because it is used on the outersurface of a display. Further, evenness in thickness of the film(coating) is also important, to attain low reflectance performance.Regarding the coating-type material, both excellent coating property andleveling property are also demanded as important factors.

To realize high resistance to abrasion in a thin film of about 100 nm inthickness, it is important to enhance both the mechanical strength ofthe coating and the adhesive property to a subbing layer. Known meansfor lowering the refractive index of the aforementioned material aresuch as (1) incorporation of a fluorine atom, and (2) reduction ofdensity (incorporation of voids). However, a problem arises that themechanical strength of the coating and the adhesive property areimpaired by these means, which results in lowering of resistance toabrasion.

The resistance to abrasion is remarkably improved by imparting a slidingproperty to the surface, while keeping the refractive index as low aspossible. To impart the sliding property, such means as incorporatingfluorine, and incorporating silicone, are effective. These means, whichcan reduce surface tension, are also expected to impart a levelingproperty, which is another target to improve. When a low refractiveindex layer contains a fluorine-containing polymer, the low refractiveindex layer itself has a sliding property. However, it is difficult toobtain a satisfactory sliding property by the single use of afluorine-based material having a short side chain in which about 50 mass% of a hydrocarbon-based copolymer component is incorporated, to impartsolubility to a solvent. Therefore, the fluorine-based material hashitherto been used in combination with a silicone compound.

Addition of a small amount of a silicone compound to the materials of alow refractive index layer remarkably improves both the sliding propertyand resistance to abrasion. Further, in addition to the slidingproperty, such effects as water repellency and an anti-stain(anti-fouling) property are also obtained. However, on the other hand,the addition of a silicone compound causes various problems related tocompatibility with the materials of a low refractive index layer(related to transparency of the coating); bleeding out with the lapse oftime or under a condition of high temperature; transfer of a siliconecomponent to a contact medium, and both deterioration of the performanceand contamination of production lines due to these problems.Particularly in the anti-reflection film, formation of haze, due toinsufficiency in compatibility, is a serious problem, because it impairsoptical performance. Further, when a film after coating is rolled,adhesion of silicone to a back surface of the coating constitutes anobstacle to a subsequent processing step, which results in a seriousproblem. In this situation, there is a need to develop a technology toeffectively segregate only a silicone site on the surface of a lowrefractive index layer, while effectively anchoring the remaining sitebonding to the silicone site in the coating of the low refractive indexlayer.

Regarding proposal for resolving these problems, JP-A-11-189621 (“JP-A”means an unexamined published Japanese patent application),JP-A-11-228631, and JP-A-2000-313709 disclose a fluorine-containingolefin copolymer having a polysiloxane block copolymerized componentincorporated therein, using a silicone macroazo initiator, and itsapplication to an anti-reflection film. This method remarkably improvesboth evenness and durability of the coating. However, to arbitrarilycontrol the sliding property of a material, some operations during theproduction of fluorine-containing olefin copolymers are needed, such asincreasing the amount of a silicone macroazo initiator. In theproduction of polysiloxane-incorporated fluorine-containing olefincopolymers, if the amount of the silicone macroazo initiator isincreased to raise the content of polysiloxane component, isolationperformance of the produced polymer, by means of reprecipitation, islowered. In addition, elimination of the remaining initiator or acomponent formed by mutual radical-coupling of initiator species,becomes very difficult. Therefore, it is not always easy to control theincorporated amount of the polysiloxane component.

From the aforementioned situation, there is a need to develop atechnology by which the incorporated amount of the silicone componentcan be arbitrarily controlled without impairing evenness of a coating ofa low-refractive-index layer.

SUMMARY OF THE INVENTION

The present invention is an anti-reflection film, which has alow-refractive-index layer formed by hardening a composition, saidcomposition containing a polysiloxane compound having a reactive organicfunctional group represented by formula 1, and a perfluoroolefincopolymer:

wherein, in formula 1, R¹, R², R³ and R⁴ each represent a substituenthaving 1 to 20 carbon atoms; when there are a plurality of any of R¹,R², R³ or R⁴, R¹s, R²s, R³s or R⁴s each are the same or different fromeach other; at least one of R¹, R³ and R⁴ represents the reactiveorganic functional group; x is an integer that is within the range of1≦x≦4; y is an integer that is within the range of 10≦y≦500; z is aninteger that is within the range of 0≦z≦500; and said polysiloxanecompound may be a random copolymer or a block copolymer.

Further, the present invention is an anti-reflection film, which has theabove-mentioned anti-reflection film on a transparent support.

Further, the present invention is an image display device, whichcomprises the anti-reflection film.

Other and further features and advantages of the invention will appearmore fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(a) and 1(b) each are a cross-sectional view schematicallyshowing a layer structure in the case that the anti-reflection film(membrane) of the present invention is a multilayer film. FIG. 1(a)shows an example of 4-layer structure. FIG. 1(b) shows an example of5-layer structure.

DETAILED DESCRIPTION OF THE INVENTION

According to the present invention, there is provided the followingmeans:1) An anti-reflection film, having a low-refractive-index layer formedby hardening a composition, said composition containing a polysiloxanecompound having a reactive organic functional group represented byformula 1, and a perfluoroolefin copolymer:

wherein, in formula 1, R¹, R², R³ and R⁴ each represent a substituenthaving 1 to 20 carbon atoms; when there are a plurality of any of R¹,R², R³ or R⁴, R¹s, R²s, R³s or R⁴s each are the same or different fromeach other; at least one of R¹, R³ and R⁴ represents the reactiveorganic functional group; x is an integer that is within the range of1≦x≦4; y is an integer that is within the range of 10≦y≦500; z is aninteger that is within the range of 0≦z≦500; and said polysiloxanecompound may be a random copolymer or a block copolymer.

2) The anti-reflection film according to the preceding item 1), whereina coating liquid composition for the low-refractive-index layer furthercomprises a hardening agent.

3) The anti-reflection film according to the preceding item 1) or 2),wherein the perfluoroolefin copolymer or the hardening agent describedin the above item 1) or 2) has a group having a reactive partialstructure same as the reactive organic functional group incorporated inthe polysiloxane compound.4) The anti-reflection film according to any of the preceding items 1)to 3), wherein the reactive organic functional group described in theabove items 1) to 3) is a ring-opening polymerizable group or a radicalpolymerizable group.5) The anti-reflection film according to any of the preceding items 1)to 4), wherein the reactive organic functional group described in theabove item 4) is an epoxy group, an oxetanyl group, or a (meth)acryloylgroup.6) The anti-reflection film according to any of the preceding items 1)to 5), wherein the perfluoroolefin copolymer described in the aboveitem 1) is represented by formula 2:

wherein, in formula 2, Rf¹ represents a perfluoroalkyl group having 1 to5 carbon atoms; Rf² represents a fluorine-containing alkyl group having1 to 30 carbon atoms, said fluorine-containing alkyl group having astraight chain, branched chain, or alicyclic structure; A represents acomponent having at least one reactive group that is capable ofinvolving in a cross-linking reaction; B represents an optionalcomponent; a, b, c and d each represent a mole fraction (%) of eachcomponent, in which a, b, c and d satisfy the following conditions:5≦a≦70, 0≦b≦90, 5≦c≦95, 0≦d≦90.7) The anti-reflection film according to the preceding item 6), whereinthe component A of the perfluoroolefin copolymer described in the aboveitem 6) at least has any of a (meth)acryloyl group, an epoxy group or anoxetanyl group.8) The anti-reflection film according to any of the preceding items 1)to 7), wherein the coating liquid composition for thelow-refractive-index layer described in the above items 1) to 7) furthercontains silica fine particles having an average particle size of 5 to50 nm.9) The anti-reflection film according to any of the preceding items 1)to 8), which has a high-refractive-index layer containing inorganic fineparticles, provided between the low-refractive-index layer described inthe above items 1) to 8) and a support.10) An anti-reflection film, having the anti-reflection film accordingto any of the preceding items 1) to 9), on a transparent support.11) An image display device, comprising the anti-reflection filmaccording to the preceding item 10).

The term “perfluoroolefin copolymer” herein used refers to a copolymercomposed of perfluoroolefin as at least one of copolymer components.

The anti-reflection film of the present invention has a low refractiveindex layer formed by hardening a composition that at least contains apolysiloxane compound having a reactive organic functional group, saidpolysiloxane compound being represented by formula 1 described above,and a perfluoroolefin copolymer.

The anti-reflection film may have a single-layer construction consistingof only one low refractive index layer, or alternatively a multi-layerconstruction in which a middle refractive index layer, ahigh-refractive-index layer, and a low refractive index layer aresuperimposed together with a hard coat layer and the like. Theanti-reflection film having such multi-layer construction is preferable.Especially preferred are those having the multi-layer construction inwhich at least three layers of the middle refractive index layer, thehigh-refractive-index layer, and the low refractive index layer aresuperimposed. Such anti-reflection film may be directly formed (in-situ)on an image display device and the like, but it is preferable that apreviously-formed anti-reflection film that may have a transparentsupport is provided onto an image display device.

{Example of a Preferable Layer Structure of the Anti-reflection Film}

With reference to FIGS. 1(a) and 1(b), typical examples of layerstructure of the anti-reflection film of the present invention will beexplained.

FIGS. 1(a) and 1(b) are sectional schematic views each illustrating anexample of various preferable layer structures of the anti-reflectionfilm of the present invention. The embodiment shown in FIG. 1(a) has alayer structure wherein a transparent support (4), a hard coat layer(3), a high-refractive-index layer (2) and a low-refractive-index layer(1) are arranged in this order. In an anti-refraction film having ahigh-refractive-index layer (2) and a low-refractive-index layer (1), asthe one shown in FIG. 1(a), it is preferable that thehigh-refractive-index layer satisfy the conditions shown by thefollowing expression (I) and the low-refractive-index layer satisfy theconditions shown by the following expression (II), respectively, asdescribed in JP-A-59-50401: $\begin{matrix}{{\frac{m}{4}\lambda \times 0.7} < {n_{1}d_{1}} < {\frac{m}{4}\lambda \times 1.3}} & (I)\end{matrix}$

wherein m is a positive integral number (generally 1, 2 or 3), n₁ is arefractive index of the high-refractive-index layer, and d₁ is athickness (nm) of the high-refractive-index layer; $\begin{matrix}{{\frac{n}{4}\lambda \times 0.7} < {n_{2}d_{2}} < {\frac{n}{4}\lambda \times 1.3}} & ({II})\end{matrix}$

wherein n is a positive odd number (generally 1), n₂ is a refractiveindex of the low-refractive-index layer, and d₂ is a thickness (nm) ofthe low-refractive-index layer.

The refractive index n₁ of the high-refractive-index layer is generallyhigher at least by 0.05 than that of the transparent film. Therefractive index n₂ of the low-refractive-index layer is generally lowerat least by 0.1 than that of the high-refractive-index layer and lowerat least by 0.05 than that of the transparent film. Further, therefractive index n1 of the high-refractive-index layer is generally inthe range of 1.57 to 2.40.

The embodiment shown in FIG. 1(b) has a layer structure wherein atransparent support (4), a hard coat layer (3), amiddle-refractive-index layer (5), a high-refractive-index layer (2) anda low-refractive-index layer (1) are arranged in this order. In ananti-refraction film having a middle-refractive-index layer (5), ahigh-refractive-index layer (2) and a low-refractive-index layer (1), asthe one shown in FIG. 1(b), it is preferable that themiddle-refractive-index layer satisfy the conditions shown by thefollowing expression (III), the high-refractive-index layer satisfy theconditions shown by the following expression (IV), and thelow-refractive-index layer satisfy the conditions shown by the followingexpression (V), respectively, as described in JP-A-59-50401:$\begin{matrix}{{\frac{h}{4}\lambda \times 0.7} < {n_{3}d_{3}} < {\frac{h}{4}\lambda \times 1.3}} & ({III})\end{matrix}$

wherein h is a positive integral number (generally 1, 2 or 3), n₃ is arefractive index of the middle-refractive-index layer, and d₃ is athickness (nm) of the middle-refractive-index layer; $\begin{matrix}{{\frac{j}{4}\lambda \times 0.7} < {n_{4}d_{4}} < {\frac{j}{4}\lambda \times 1.3}} & ({IV})\end{matrix}$

wherein j is a positive integral number (generally 1, 2 or 3), n₄ is arefractive index of the high-refractive-index layer, and d₄ is athickness (nm) of the high-refractive-index layer; $\begin{matrix}{{\frac{k}{4}\lambda \times 0.7} < {n_{5}d_{5}} < {\frac{k}{4}\lambda \times 1.3}} & (V)\end{matrix}$

wherein k is a positive odd number (generally 1), n₅ is a refractiveindex of the low-refractive-index layer, and d₅ is a thickness (nm) ofthe low-refractive-index layer.

The refractive index n₃ of the middle-refractive-index layer isgenerally in the range of 1.5 to 1.7. The refractive index n₄ of thehigh-refractive-index layer is generally in the range of 1.7 to 2.2.

Further, λ in formulae (I) to (V) represents a wavelength of visibleradiation within the range of 380 to 680 nm. The terms “high-refractiveindex”, “middle-refractive index”, and “low-refractive index” describedherein mean relative magnitude of the refractive indices among layers.For example, the middle-refractive-index layer can be prepared by amethod changing the content of high-refractive-index inorganic fineparticles contained in the high-refractive-index layer, or othermethods.

The anti-reflection film having the above-described layer structure atleast has a low-refractive-index layer improved according to the presentinvention.

{Low Refractive Index Layer}

The low-refractive-index layer is disposed above thehigh-refractive-index layer, as shown in FIGS. 1(a) and (b). The upperside of the low-refractive-index layer is a surface of theanti-reflection film.

The low-refractive-index layer has a refractive index preferably in therange of 1.20 to 1.49, more preferably in the range of 1.20 to 1.45, andespecially preferably in the range of 1.20 to 1.43.

The low refractive index layer has a thickness preferably in the rangeof 50 to 400 nm, and more preferably in the range of 50 to 200 nm. Ahaze of the low-refractive-index layer is preferably 3% or less, morepreferably 2% or less, and most preferably 1% or less. A practicalmechanical strength of the low-refractive-index layer is preferably H orgreater, more preferably 2H or greater, and most preferably 3H orgreater, in terms of pencil grade according to the pencil hardness testunder the load of 1 Kg.

The low-refractive-index layer according to the present invention isformed by hardening a composition, which composition contains thepolysiloxane compound having a reactive organic functional group, thepolysiloxane compound being represented by formula 1 described above,and the perfluoroolefin copolymer.

A mass ratio of the polysiloxane compound to the perfluoroolefincopolymer is preferably from 0.05:100 to 20:100, more preferably from0.5:100 to 5:100.

In formula 1, R¹ to R⁴ each represent a substituent having 1 to 20carbon atoms, preferably a substituent having 1 to 10 carbon atoms. Whenthere are a plurality of R¹, R², R³ or R⁴, each of R¹s, R²s, R³s, or R⁴smay be the same or different from each other. At least one of R¹, R³,and R⁴ represents the reactive organic functional group.

The term “reactive organic functional group” used in the presentinvention refers to a group capable of forming a bond upon reacting witha cross-linkable group in the hardening agent or the perfluoroolefincopolymer, both of which are used to form the low-refractive-indexlayer. Examples of the reactive organic functional group include a grouphaving an active hydrogen atom (for example, a hydroxyl group, acarboxyl group, an amino group, a carbamoyl group, a mercapto group, aβ-ketoester group, a hydrosilyl group, a silanol group), a cationicpolymerizable group (for example, an epoxy group, an oxetanyl group, anoxazolyl group, a vinyloxy group), a group having an unsaturated doublebond capable of being involved in addition or polymerization of radicalspecies (for example, an acryloyl group, a methacryloyl group, an allylgroup), a hydrolytic silyl group (for example, an alkoxysilyl group, anacryloxysilyl group), and a group that can be substituted with an acidanhydride, an isocyanate group or a nucleophilic reagent (for example,an active halogen atom, a sulfonic acid ester).

These reactive groups are important to both compatibility of a siliconecomponent in the low-refractive-index layer, and prevention of thesilicone component from bleeding out of the low-refractive-index layer.The reactive groups are properly selected in accordance with reactivityof a hardening agent or a perfluoroolefin copolymer to be contained inthe low-refractive-index layer. It is particularly preferable in thepresent invention that the perfluoroolefin copolymer or the hardeningagent has the same functional group as the reactive organic functionalgroup set forth in formula 1. These functional groups are especiallypreferably a cationic ring-opening polymerizable group (an epoxy groupor an oxetanyl group is especially preferable) and a radicalpolymerizable group (a (meth)acryloyl group is especially preferable).

In formula 1, R² represents a substituted or unsubstituted organicmoiety having 1 to 20 carbon atoms, preferably an alkyl group having 1to 10 carbon atoms (e.g., a methyl group, an ethyl group, a hexylgroup), a fluoroalkyl alkyl group preferably having 1 to 10 carbon atoms(e.g., a trifluoromethyl group, a pentafluoroethyl group), or an arylgroup having 6 to 20 carbon atoms (e.g., a phenyl group, a naphthylgroup), more preferablyl an alkyl group or fluorinated alkyl grouphaving 1 to 5 carbon atoms, or a phenyl group, and especially preferablya methyl group.

x represents an integer that is embraced in the range: 1≦x≦4. yrepresents an integer that is embraced in the range: 10≦y≦500,preferably 50≦y≦400, and particularly preferably 100≦y≦300. z representsan integer that is embraced in the range: 0≦z≦500. Preferably, z and ysatisfy the following conditions: 0≦z≦y, especially preferably 0≦z≦0.5y.

The polysiloxane structure in the compound represented by formula 1 maybe a homopolymer consisting of only the recurring unit (—OSi(R²)₂—) inwhich two substituents (R²) are the same, or it may be a randomcopolymer or a block copolymer each formed by combining differentrecurring units in which said two substituents (R²) are different fromeach other.

A molecular mass of the compound represented by formula 1 is preferablyin the range of 10³ to 10⁶, more preferably in the range of 5×10³ to5×10⁵, and especially preferably in the range of 10⁴ to 10⁵.

As the polysiloxane compound represented by formula 1, use can be madeof those commercially available, such as KF-100T, X-22-169AS, KF-102,X-22-3701IE, X-22-164B, X-22-5002, X-22-173B, X-22-174D, X-22-167B andX-22-161AS (each trade name, manufactured by Shin-Etsu Chemical Co.,Ltd.), AK-5, AK-30 and AK-32 (each trade name, manufactured by ToagoseiCo., Ltd.), SILAPLANE FM0275 and SILAPLANE FM0721 (each trade name,manufactured by CHISSO CORPORATION). Alternatively, the polysiloxanecompound of formula 1 can be synthesized, for example, by a method ofincorporating a functional group in a commercially availablepolysiloxane compound having such a reactive group as a hydroxyl group,an amino group or a mercapto group.

Preferable specific examples of the polysiloxane compound represented byformula 1 and useful in the present invention, are shown below. However,the present invention is not limited to these compounds.

n S-(1)  50 S-(2) 100 S-(3) 200 S-(4) 500 S-(5)

S-(6)

S-(7)

S-(8)

S-(9)

S-(10)

S-(11)

S-(12)

S-(13)

S-(14)

S-(15)

S-(16)

S-(17)

S-(18)

S-(19)

S-(20)

S-(21)

S-(22)

S-(23)

S-(24)

S-(25)

S-(26)

S-(27)

S-(28)

S-(29)

S-(30)

S-(31)

S-(32)

In the present invention, the compound represented by the aforementionedformula 1 is added preferably in the range of 0.01 to 20 mass %, morepreferably in the range of 0.05 to 10 mass %, and especially preferablyin the range of 0.5 to 5 mass %, to the total solid content to form thelow-refractive-index layer. This compound is added preferably so as tobecome a coefficient of kinetic friction of 0.2 or less, more preferably0.15 or less, in which the coefficient of kinetic friction is measuredon the surface of the low-refractive-index layer under the conditions of25° C. and 60% RH by means of a kinetic-friction measuring equipment(HEIDON-14, trade name), using a 5-mmø stainless steel ball with load of0.98N and the speed of 60 cm/min.

In the low-refractive-index layer according to the present invention, aperfluoroolefin copolymer is incorporated as an essential component,together with the compound represented by the aforementioned formula 1.A general form of the perfluoroolefin copolymer useful in the presentinvention is a random copolymer of a perfluoroolefin and a vinyl etheror vinyl ester. This copolymer preferably has a cross-linking reactivegroup.

As the perfluoroolefin, those having 3 to 7 carbon atoms are preferable.Among them, perfluoropropylene and perfluorobutylene are more preferablefrom the viewpoint of polymerization reactivity. Particularly,perfluoropropylene is preferable from the viewpoint of availability.

A content of the perfluoroolefin component in the perfluoroolefincopolymer is generally in the range of 5 mole % to 70 mole %. For makingrefractive index of a material lower, it is effective to increase anincorporated rate of the perfluoroolefin component. However, in ageneral solvent-system radical polymerization reaction, incorporation ofthe perfluoroolefin is limited up to a range of about 50 mole % to about70 mole % due to polymerization reactivity. Accordingly, incorporationover the rate of about 70 mole % is difficult. In the present invention,the content of a perfluoroolefin component is preferably in the range of30 to 60 mole %, especially preferably in the range of 40 to 55 mole %.

The perfluoroolefin copolymer used in the present invention preferablyhas a cross-linking reactive group. Examples of the cross-linkingreactive group are those described as examples of the reactive organicfunctional group in the foregoing explanation regarding the polysiloxanecompound represented by formula 1. Preferable examples are also the sameas the aforementioned preferable reactive organic functional groups. Inthe present invention, a cross-linking group having reactivity with afunctional group of the polysiloxane compound of formula 1 is morepreferable. Particularly preferably the perfluoroolefin copolymer andthe polysiloxane compound have the same functional group.

An incorporation amount of components having these cross-linkingreactive groups is generally in the range of 5 to 95 mole %, preferablyin the range of 10 to 70 mole %, and especially preferably in the rangeof 30 to 60 mole %.

Preferable examples of the polymerization unit (A) having across-linking reactive group in the perfluoroolefin copolymer that canbe used in the present invention are shown below. However, the presentinvention is not limited to these units.

For making the refractive index further lower, the perfluoroolefincopolymer used in the present invention is preferably co-polymerizedwith a fluorine-containing vinyl ether represented by M1 describedbelow. The copolymerizable component may be incorporated in theresulting perfluoroolefin copolymer generally in the range of 5 to 90mole %, preferably in the range of 5 to 50 mole %, and especiallypreferably in the range of 10 to 30 mole %.

In formula M1, Rf² represents a fluorine-containing alkyl group having 1to 30 carbon atoms, preferably 1 to 20 carbon atoms, especiallypreferably 1 to 15 carbon atoms. The fluorine-containing alkyl group mayhave a straight chain (e.g., —CF₂CF₃, —CH₂(CF₂)₄H, —CH₂(CF₂)₈CF₃,—CH₂CH₂(CF₂)₄H), a branched structure (e.g., CH(CF₃)₂, CH₂CF(CF₃)₂,CH(CH₃)CF₂CF₃, CH(CH₃)(CF₂)₅CF₂H), an alicyclic structure (preferably a5- or 6-membered ring, e.g., a perfluorocyclohexyl group, aperfluorocyclopentyl group, and alkyl groups substituted with any ofthese cyclic groups), or an ether moiety (e.g., CH₂OCH₂CF₂CF₃,CH₂CH₂OCH₂C₄F₈H, CH₂CH₂OCH₂CH₂C₈F₁₇, CH₂CH₂OCF₂CF₂OCF₂CF₂H).

The above-described monomers represented by M1 can be synthesized, forexample, according to a method of subjecting a fluorine-containingalcohol to react with a split-off group-substituted alkyl vinyl ether,such as a vinyloxyalkyl sulfonate or a vinyloxyalkyl chloride, in thepresence of a basic catalyst, as described in Macromolecules, 32(21),7122 (1999), and JP-A-2-721; a method of exchanging a vinyl group bymixing a fluorine-containing alcohol with a vinyl ether such as butylvinyl ether, in the presence of a catalyst such as palladium, asdescribed in International Patent Application (PCT) No. 92/05135; and amethod of performing a dehydrobromide reaction in the presence of analkali catalyst, after a reaction of a fluorine-containing ketone withdibromoethane in the presence of a potassium fluoride catalyst, asdescribed in U.S. Pat. No. 3,420,793.

Preferable examples of the components represented by M1 are shown below,but the present invention is not limited to these.

Further, other copolymerizable components that may be optionally usedare properly selected from various viewpoints such as hardness, adhesionto a substrate, solubility to a solvent, and transparency.

Examples of said other copolymerizable components include vinyl ethers,such as methyl vinyl ether, ethyl vinyl ether, t-butyl vinyl ether,n-butyl vinyl ether, cyclohexyl vinyl ether, and isopropyl vinyl ether;and vinyl esters, such as vinyl acetate, vinyl propionate, vinylbutyrate, and vinyl cyclohexanecarboxylate.

An incorporation amount of these copolymerizable components is generallyin the range of 0 to 90 mole %, preferably in the range of 0 to 50 mole%, and especially preferably in the range of 0 to 30 mole %.

A particularly preferable form of the perfluoroolefin copolymer used inthe present invention is represented by formula 2.

In formula 2, Rf¹ represents a perfluoroalkyl group having 1 to 5 carbonatoms. As to the monomer that constitutes a portion represented by—CF₂CF(Rf¹)—, the foregoing explanation regarding the examples of theperfluoroolefin component is applicable. Rf² represents afluorine-containing alkyl group having 1 to 30 carbon atoms, preferably1 to 20 carbon atoms, and especially preferably 1 to 15 carbon atoms. Asto the fluorine-containing alkyl group, the foregoing explanation of thefluorine-containing alkyl group set forth with regard to thefluorine-containing vinyl ether is applicable. A and B each represent aconstitutional unit having a cross-linking reactive group and anoptional constitutional unit as explained above, respectively.

Specific examples of the polymer used in the present invention are shownin Tables 1 and 2 below. However, the present invention is not limitedto these polymers.

In Tables 1 and 2, these polymers are described as a combination ofpolymerization units.

TABLE 1 Perfluoroolefin copolymer P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 P11 P12P13 P14 P15 P16 P17 Fundamental Hexafluoro- 50 50 50 50 50 50 55 45 5050 50 50 50 50 50 50 50 constitution of propylene fluorine- M1-(1) 10 2010 20 10 20 10 10 containing M1-(5)  5 10 10 polymer (mole A-(1) 50 4040 45 40 30 45 55 fraction (%)) A-(14) 10 A-(17) 50 40 30 A-(25) 50 4030 A-(26) 40 A-(28) 40 40

TABLE 2 Perfluoroolefin copolymer P18 P19 P20 P21 P22 P23 P24 P25Fundamental Hexafluoropropylene 50 50 50 50 50 50 50 50 constitution ofA-(1) 40 40 fluorine- A-(25) 40 40 containing A-(26) 40 40 polymer (moleA-(28) 40 40 fraction (%)) Ethyl vinyl ether 10 10 10 10 t-Butyl vinylether 10 10 10 10

The synthesis of the perfluoroolefin copolymer that can be used in thepresent invention can be conducted according to various polymerizationmethods such as solution polymerization, precipitation polymerization,suspension polymerization, precipitation polymerization, masspolymerization, and emulsion polymerization. Further, at this time,synthesis can be performed according to known operations such as a batchprocess, a semi-continuous process and a continuous process.

As a method of initiating polymerization, known are a method of using aradical initiator and a method of irradiating light or radiation. Thesepolymerization methods and methods of initiating polymerization aredescribed in, for example, “Kobunshi Gosei Hoho” by Teiji Turuta,Revised Edition (published by Nikkankogyo shinbunsha, 1971) and“Kobunshi Gosei no Jikkenho” by Takayuki Ohtu and Masaetu Kinoshita(published by Kagakudojin, 1972) pp. 124 to 154.

Among these polymerization methods, solution polymerization in which aradical initiator is used is particularly preferable. Examples of thesolvent for use in the solution polymerization include various organicsolvents such as ethyl acetate, butyl acetate, acetone, methyl ethylketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, dioxane,N,N-dimethylformamide, N,N-dimethylacetoamide, benzene, toluene,acetonitrile, methylenechloride, chlorofolm, dichloroethane, methanol,ethanol, 1-propanol, 2-propanol and 1-butanol. These solvents may beused singly or in a combination of at least 2 kinds of solvents, oralternatively as a mixed solvent with water.

Polymerization temperature needs to be selected in relation to themolecular weight of the perfluoroolefin copolymer to be formed, the kindof an initiator, and the like. Polymerization can be performed in a widerange of from 0° C. or lower to 100° C. or higher, but it is preferablyperformed in the range of from 50° C. to 100° C.

Reaction pressure may be optionally selected, but it is generally in therange of 1 to 100 kg/cm², particularly preferably about 1 to about 30kg/cm². Reaction time is generally in the range of about 5 to about 30hours.

As the re-precipitation solvent for the thus-obtained perfluoroolefincopolymer, isopropanol, hexane and methanol are preferable.

Regarding the perfluoroolefin copolymer used in the present invention, across-linking reactive group may be previously introduced into a monomerthat is used to prepare said copolymer. Alternatively, after preparationof a perfluoroolefin copolymer having a hydroxyl group or the like, thecross-linking reactive group may be introduced into the perfluoroolefincopolymer upon a high-molecular reaction in which said co-polymer issubjected to a reaction with an acid halide such as (meth)acrylic acidchloride, or an acid anhydride such as (meth)acrylic acid anhydride.

In order to harden a low-refractive-index layer-forming compositionaccording to the present invention, a hardening catalyst or a hardeningagent may be optionally blended with the composition. Known hardeningcatalysts or agents may be used. They are properly selected inaccordance with reactivity of both the polysiloxane compound representedby formula 1 and the cross-linking reactive portion of theperfluoroolefin copolymer. The above-mentioned composition is generallyin the form of a liquid.

When the perfluoroolefin copolymer has a radical polymerizableunsaturated double bond (e.g., an acryloyl group, a methacryloyl group),addition of a radical polymerization initiator is preferable.

The radical polymerization initiator may be any one of the compound thatgenerates radicals by the action of heat, and the compound thatgenerates radicals by the action of light.

As the compound that initiates radical polymerization by the action ofheat, for example, organic or inorganic peroxides, and organic azo ordiazo compounds may be used.

Specific examples of the above-mentioned compounds include organicperoxides such as benzoyl peroxide, benzoyl halogenoperoxide, lauroylperoxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, andbutyl hydroperoxide; inorganic peroxides such as hydrogen peroxide,ammonium persulfate, and potassium persulfate; azo compounds such as2-azo-bis-isobutylonitrile, 2-azo-bis-propionitrile, and2-azo-bis-cyclohexanedinitrile; and diazo compounds such asdiazoaminobenzene and p-nitrobenzene diazonium.

In case of the compound that initiates radical polymerization by theaction of heat, the film is hardened by the irradiation of active energyrays.

Examples of these photo-radical polymerization initiators includeacetophenones, benzoins, benzophenones, phosphine oxides, ketals,anthraquinones, thioxanthones, azo compounds, peroxides,2,3-dialkyldione compounds, disulfide compounds, fluoroamine compoundsand aromatic sulfonium compounds. Examples of the acetophenones include2,2-diethoxyacetophenone, p-dimethoxyacetophenone,1-hydroxydimethylphenylketone, 1-hydroxycyclohexyl phenylketone,2-methyl-4-methylthio-2-morpholinopropiophenone and2-benzyl-2-dimetylamino-1-(4-morpholinophenyl)butanone. Examples of thebenzoines include benzoine benzenesulfonic acid ester, benzoinetoluenesulfonic acid ester, benzoine methyl ether, benzoine ethyl ether,and benzoine isopropyl ether. Examples of the benzophenones includebenzophenone, 2,4-dichloro benzophenone, 4,4-dichlorobenzophenone, andp-chlorobenzophenone. Examples of the phosphine oxides include2,4,6-trimethylbenzoyldiphenylphosphine oxide. A sensitizing dye may bealso preferably used in combination with these photo-radicalpolymerization initiators.

An addition amount of a compound that initiates a radical polymerizationby the action of heat or light is an amount necessary to initiatepolymerization of a carbon-carbon double bond. Generally, the amount ispreferably in the range of 0.1 to 15 mass %, more preferably in therange of 0.5 to 10 mass % and especially preferably in the range of 2 to5 mass %, based on the total solid content of thelow-refractive-index-layer-forming composition, respectively.

In the case that the above-mentioned perfluoroolefin copolymer has aradical-polymerizable unsaturated double bond, the copolymer may not beused in combination with another hardening agent. However, as ahardening agent, a polyfunctional unsaturated monomer that is capable ofreacting with such unsaturated bond may be added. Examples of thepolyfunctional unsaturated monomer include (meth)acrylate monomersderived from a polyhydric alcohol, such as dipentaerythritolhexa(meth)acrylate.

In the case where these hardeners are added, the addition amount ofthese hardeners is preferably in the range of about 0.5 to about 300mass parts, especially preferably in the range of about 5.0 to about 100mass parts, based on 100 mass parts of the above-mentionedperfluoroolefin copolymer.

In the case that the cross-linking reactive portion of theperfluoroolefin copolymer has a cationic copolymerizable group (e.g., anepoxy group, an oxetanyl group, an oxazolyl group, a vinyloxy group), itis preferable to add a compound that generates an acid (acid catalyst)by the action of light as a hardening catalyst.

As examples of the compound that generates acids by the action of light,various compounds are described in, for example, “Imeizingu yo YukiZairyo” edited by Yuki Erekutoronikusu Zairyo Kenkyukai (BunshinShuppan), pp. 187 to 198, and JP-A-10-282644. The compounds such asthose known from these publications may be used in the presentinvention. Specific examples of these compounds include various kinds ofonium salts such as diazonium salts, ammonium salts, phosphonium salts,iodonium salts, sulfonium salts, selenonium salts and arsonium salts,each of which has a counter ion such as RSO₃ ⁻ (R represents an alkylgroup, or an aryl group), AsF₆ ⁻, SbF₆ ⁻, PF₆ ⁻ and BF₄ ⁻; organichalides such as oxadiazole derivatives and S-triazine derivatives, eachof which is substituted with a trihalomethyl group; organic acid esterssuch as o-nitrobenzyl esters, benzoin esters and imino esters; anddisulfone compounds. Among these compounds, onium salts are preferable.Particularly, sulfonium salts and iodonium salts are preferable.

A sensitizing dye may also preferably be used in combination with thesecompounds that generate an acid by the action of light. In the presentinvention, the addition amount of such compound that accelerates ahardening reaction by the action of light is preferably in the range of0.1 to 15 mass %, more preferably in the range of 0.5 to 10 mass % andespecially preferably in the range of 2 to 5 mass %, based on the totalsolid content of the low refractive index layer-forming composition,respectively.

In this time, it is not necessary to use such a compound in combinationwith another hardening agent. However, the aforementioned compound maybe used in combination with a polyfunctional compound, as a hardeningagent, that is able to react with these cationic polymerizable groups(for example, compounds having a plurality of the cationic polymerizablegroup in a molecule, polybasic acids such as pyromellitic acid,trimellitic acid, phtharic acid, maleic acid, succinic acid).

In the case where these hardeners are added, the addition amount ofthese hardeners is preferably in the range of about 0.5 to about 300mass parts, especially preferably in the range of about 5.0 to about 100mass parts, based on 100 mass parts of the above-mentionedperfluoroolefin copolymer.

For example, when the polymer contains a hydrolysable silyl group thatacts as a part having a hardening reactivity, known acid or basecatalyst that acts as a catalyst of sol-gel reaction may be mixed.Examples of these catalysts include inorganic Brφnsted acids such ashydrochloric acid, sulfuric acid and nitric acid; organic Brφnsted acidssuch as oxalic acid, acetic acid, formic acid, methane sulfonic acid andp-toluene sulfonic acid; Lewis acids such as dibutyl tin dilaurate,dibutyl tin diacetate, dibutyl tin dioctate, triisopropoxy aluminum, andtetrabutoxy zirconium; inorganic bases such as sodium hydroxide,potassium hydroxide and ammonia; and organic bases such astriethylamine, pyridine, and tetramethyl ethylenediamine. Particularlyacid catalysts are preferable. Among them, organic Brφnsted acids suchas p-toluene sulfonic acid, and Lewis acids such as dibutyl tindilaurate are preferable.

The addition amount of these hardening catalysts may be varied over awide range in accordance with the kinds of the catalyst and the parthaving a hardening reactivity. Generally, the addition amount ispreferably 0.1 to 15 mass %, more preferably 0.5 to 10 mass %, andespecially preferably 2 to 5 mass %, to the total solid content in thelow-refractive-index-layer-forming composition.

Further, a compound that generates a hardening accelerator, such as anacid and a base, by the action of light may be used from the viewpointof storage stability of the low-refractive-index layer-formingcomposition. When these compounds are used, the film can be cured by theirradiation of active energy rays.

As the compound that generates an acid by the action of light, thosecompounds explained above as a hardening catalyst for acationic-polymerizable group are exemplified. As the compound thatgenerates a base by the action of light, known compounds can be used.Specifically, compounds such as nitrobenzyl carbamates and dinitrobenzylcarbamates can be exemplified.

In the present invention, it is particularly preferable to use thecompound that generates an acid by the action of light. A sensitizingdye can be preferably used in combination with the above-mentionedcompound that generates an acid or base by the action of light. Incommon with the above-mentioned ones, an addition amount of the compoundthat accelerates a hardening reaction by the action of light for use inthe present invention is also preferably in the range of 0.1 to 15 mass%, more preferably in the range of 0.5 to 10 mass %, and especiallypreferably in the range of 2 to 5 mass %, based on the total solidcontent in the low refractive index layer-forming composition,respectively.

In order to further accelerate hardening, a dehydrating agent may beused. Examples of the dehydrating agent include carboxylic acidorthoesters (e.g., methyl orthoformate, ethyl orthoformate, methylorthoacetate), and acid hydrides (e.g., acetic acid anhydride).

Further, the hardener may be used in combination with another type ofhardener such as an organic silicate (for example, various kinds ofalkoxysilane hydrolysis partial condensation products) and the like, asdescribed in JP-A-61-258852.

In the case where these hardeners are used, the addition amount of thehardeners is preferably in the range of 0.5 to 300 mass parts, andparticularly preferably in the range of 5.0 to 100 mass parts, based on100 mass parts of the above-mentioned perfluoroolefin copolymer.

In the case where the hardening reactive part is a group having anactive hydrogen atom such as a hydroxyl group, admixture of hardeners ispreferable. Examples of such hardeners include polyisocyanate-seriescompounds, aminoplasts, polybasic acids and anhydrides of these acids.

Examples of the polyisocyanate-series compounds includes polyisocyanatecompounds such as m-xylenediisocyanate, toluene-2,4-diisocyanate,hexamethylenediisocyanate, and isophoronediisocyanate; silylisocyanatecompounds such as methylsilyltriisocyanate; partial condensationproducts of these isocyanate compounds; polymers of these isocyanatecompounds; adducts of polyalcohol or a low molecular weight polyesterfilm with these isocyanate compounds; and block polyisocyanate compoundsin which the isocyanate group is blocked with a blocking agent such asphenol.

As the aminoplasts, use can be made of melamines (melamine films),guanamines (guanamine films), ureas (urea films) and the like. Amongthese compounds, preferred examples include methylol melamines in whichetherification is at least partially made by one or more kinds of loweralcohol such as methanol, ethanol, propanol and butanol (e.g.,hexamethyl-etherificated methylol melamine, hexabutyl-etherificatedmethylol melamine, methyl butyl-mixture etherificated methylol melamine,methyl-etherificated methylol melamine, butyl-etherificated methylolmelamine), and condensation products of these melamines.

Examples of the polybasic acids or anhydrides of these acids includearomatic polycarboxylic acids, and anhydrides of these acids, such aspyromellitic acid, pyromellitic acid anhydride, trimellitic acid,trimellitic acid anhydride, phthalic acid, and phthalic acid anhydride;and aliphatic polycarboxylic acids or anhydrides of these acids, such asmaleic acid, maleic acid anhydride, succinic acid and succinic acidanhydride.

In the present invention, the admixture amount of each ingredient may beproperly selected. The addition amount of the hardener is preferably inthe range of about 0.5 to about 300 mass parts, especially preferably inthe range of about 5.0 to about 100 mass parts, based on 100 mass partsof the above-mentioned perfluoroolefin copolymer.

Alternatively, a fluorine-containing polymer and these hardeners may bepreviously, partially condensed before use.

In order to accelerate a hardening reaction, a catalyst that accelerateshardening may be optionally used together with the above-mentionedhardener. Examples of these catalysts include base or acid catalystsdescribed above as the hardening catalyst for a hydrolysable silylgroup. As described above, it is also preferable to use a compound thatgenerates such catalyst by the action of light. A preferable additionamount of the catalyst is also the same as the above-mentioned hardeningcatalyst for the hydrolysable silyl group.

The low-refractive-index layer-forming composition that can be used inthe present invention is generally prepared by dissolving a polysiloxanecompound represented by formula 1, a perfluoroolefin copolymer, ahardening agent and a polymerization initiator, in an arbitrarilysolvent. At this time, the concentration of the solid content may beproperly varied in accordance with various uses of the copolymer. Theconcentration is generally about 0.01 to about 60 mass %, preferablyabout 0.5 to about 50 mass %, and particularly preferably about 1 toabout 20 mass %.

The kind of the above-described solvent is not particularly limited solong as the composition containing the polymer represented by formula 1is homogeneously dissolved or dispersed in the solvent, without causingprecipitation of the same. Two or more kinds of solvents may be used incombination. Preferable examples of the solvent include ketones (e.g.,acetone, methyl ethyl ketone, methyl isobutyl ketone), esters (e.g.,ethyl acetate, butyl acetate), ethers (e.g., tetrahydrofuran,1,4-dioxane), alcohols (e.g., methanol, ethanol, isopropyl alcohol,butanol, ethyleneglycol), aromatic hydrocarbons (e.g., toluene, xylene),and water.

To the low-refractive-index layer-forming composition used in thepresent invention, colloidal silica may be further added in order toimprove film strength or a coating property. The average particlediameter of the colloidal silica is generally 5 to 50 nm, preferably 5to 30 nm, and especially preferably 8 to 20 nm. Such colloidal silicacan be prepared by subjecting tetraalkoxysilane as a row material tohydrolysis and polymerization condensation in the presence of a catalystsuch as aqueous ammonia, according to operations described by, forexample, I. M. Thomas, in Appl. Opt., 25, 1481 (1986). In addition, ascommercially available products, SNOWTEX IPA-ST and MEK-ST (each tradename) manufactured by Nissan Chemical Industries, Ltd., and AEROSIL 300,AEROSIL 130 and AEROSIL 50 (all trade names) manufactured by NipponAerosil Co., Ltd. are available.

Addition amount of colloidal silica is generally in the range of 5 to 95mass %, preferably in the range of 10 to 70 mass %, and particularlypreferably in the range of 20 to 60 mass %, based on the total solidcontent of the coated and hardened low-refractive-index layer.

In addition, various kinds of additives such as silane coupling agents,surfactants, thickeners, leveling agents and the like may be optionallyadded to the low-refractive-index layer-forming composition used in thepresent invention, if necessary.

{High- and Middle-refractive-index Layers}

In case where the anti-reflection film of the present invention has aform of a multi-layer film, the low-refractive-index layer is generallyused together with at least one layer having a higher refractive indexthan the low-refractive-index layer (i.e., the above-mentionedhigh-refractive-index layer and/or middle-refractive-index layer).

Examples of the organic material that can be utilized to form theabove-mentioned layer having a higher refractive index than thelow-refractive-index layer include a thermoplastic film (e.g.,polystylenes, polystylene copolymers, polycarbonates, polymers having anaromatic ring, heterocyclic ring or alicyclic group excludingpolystyrenes; and polymers having a halogen atom excluding a fluorineatom); a thermal film-forming composition (e.g., film-formingcompositions in which melamines, phenols or epoxies are used as ahardener); urethane-forming compositions (e.g., a combination ofalicyclic or aromatic isocyanate and polyol), and radical polymerizablecompositions (compositions containing a modified film or pre-polymer inwhich a double bond is introduced into the above-mentioned compounds(polymers and the like) so that a radical curing can be performed).Materials having a high film-forming property are preferable. In a layerhaving a higher refractive index than the above-mentioned layer,inorganic fine particles dispersed in an organic material may be alsoused. Because inorganic fine particles generally have a high refractiveindex, even an organic material having a relatively lower refractiveindex, when compared to the case where an organic material is usedalone, also can be used in the above-said layer. Examples of thesematerials include, in addition to the above-mentioned organic materials,various kinds of transparent organic materials that are able to form astable dispersion of inorganic fine particles, such as vinyl-seriescopolymers including acryl-series copolymers, polyesters, alkyd films,fibrous polymers, urethane films, various kinds of hardeners that areable to harden these materials, and compositions having a hardeningfunctional group.

Further, silicon-series compounds substituted with an organicsubstituent may be included in the above-mentioned organic materials.Examples of these silicon-series compounds are those represented by thefollowing formula, or hydrolytic products thereof:R^(a) _(m)R^(b) _(n)SiZ_((4-m-n))

in which R^(a) and R^(b) each represent an alkyl group, an alkenylgroup, an aryl group, or a hydrocarbon group substituted with halogen,epoxy, amino, mercapto, methacryloyl or cyano; Z represents ahydrolysable group selected from the group consisting of an alkoxygroup, an alkoxyalkoxy group, a halogen atom and an acyloxy group; m andn each represent 0, 1 or 2, in which m+n=1 or 2.

Preferable examples of the inorganic compound of the inorganic fineparticles dispersed in the above-mentioned organic material includeoxides of metallic element such as aluminum, titanium, zirconium andantimony. These compounds are commercially available, in the form offine particles, namely powder, or a colloidal dispersion of the fineparticles in water and/or other solvent. These fine particles arefurther mixed and dispersed in the above-mentioned organic material ororganic silicon compound for use.

As the material that forms a layer having a higher refractive index thanthe above-mentioned materials, film-forming inorganic materials that canbe dispersed in a solvent, or that are themselves liquid form (e.g.,alkoxides of various elements, organic acid salts, coordinationcompounds bonding with a coordinating compound (e.g., chelatecompounds), and inorganic polymers) are enumerated. Preferable examplesof these compounds include metal alkolate compounds such as titaniumtetraethoxide, titanium tetra-i-propoxide, titanium tetra-n-propoxide,titanium tetra-n-butoxide, titanium tetra-sec-butoxide, titaniumtetra-tert-butoxide, aluminum triethoxide, aluminum tri-i-propoxide,aluminum tributoxide, antimony triethoxide, antimony tributoxide,zirconium tetraethoxide, zirconium tetra-i-prpoxide, zirconiumtetra-n-prpoxide, zirconium tetra-n-butoxide, zirconiumtetra-sec-butoxide and zirconium tetra-tert-butoxide; chelate compoundssuch as diisopropoxy titanium bis(acetylacetonate), dibutoxy titaniumbis(acetylacetonate), diethoxy titanium bis(acetylacetonate),bis(acetylacetone zirconium), aluminum acetylacetonate, aluminumdi-n-butoxide monoethylacetoacetate, aluminum di-i-propoxidemonomethylacetoacetate and tri-n-butoxide zirconiummonoethylacetoacetate; and inorganic polymers comprising carbon zirconylammonium or zirconium as a main component. In addition to theabove-mentioned compounds, various kinds of alkyl silicates orhydrolytic product thereof, and silica in the form of fine particles(particularly a colloidal dispersion of silica gel) may also be used asan additional material that can be used in combination with theabove-mentioned compounds, even though such an additional material isrelatively low in its refractive index.

A refractive index of the high-refractive-index layer is generally inthe range of 1.70 to 2.20. The refractive index can be measured by meansof an Abbe refractometer or by estimate based on reflectance of lightfrom the surface of a layer. A thickness of the high-refractive-indexlayer is preferably in the range of 5 nm to 10 μm, more preferably inthe range of 10 nm to 1 μm, and most preferably in the range of 30 nm to0.5 μm. A haze of the high-refractive-index layer is preferably 5% orless, more preferably 3% or less, and most preferably 1% or less. Apractical mechanical strength of the high-refractive-index layer ispreferably H or harder, more preferably 2H or harder, and mostpreferably 3H or harder, in terms of pencil grade according to thepencil hardness test under the load of 1 kg.

The refractive index of the middle-refractive-index layer is adjusted soas to become a value (magnitude) between the refractive index of thelow-refractive-index layer and the refractive index of thehigh-refractive-index layer. The refractive index of themiddle-refractive-index layer is preferably in the range of 1.50 to1.70.

It is particularly preferable that inorganic fine particles and apolymer are used in the high-refractive-index layer, and that themiddle-refractive-index layer is formed adjusting so that the refractiveindex of the middle-refractive-index layer becomes lower than that ofthe high-refractive-index layer. A haze of the middle-refractive-indexlayer is preferably 3% or less.

{Other Layers}

The anti-reflection film may be further provided with a hard coat layer,a moisture-proof layer, an anti-static layer, a subbing layer (undercoat layer), and a protective layer. The hard coat layer is disposed togive a scratch resistance to the transparent support. The hard coatlayer also has a function to strengthen adhesion between the transparentsupport and a layer disposed thereon. The hard coat layer may be formedusing any one of acryl-series polymers, urethane-series polymers,epoxy-series polymers, silicon-series polymers, and/or silica-seriescompounds. A pigment may be added to the hard coat layer. Theacryl-series polymers are preferably synthesized by a polymerizationreaction of a multifunctional acrylate monomer (for example, a polyolacrylate, a polyester acrylate, a urethane acrylate, an epoxy acrylate).Examples of the urethane-series polymers include melamine polyurethane.As the silicon-series polymers, co-hydrolysis products of a silanecompound (e.g., tetraalkoxysilane, alkyltrialkoxysilane) and asilane-coupling agent having a reactive group (e.g., epoxy, methacryl)are preferably used. Two or more kinds of polymers may be used incombination. As the silica-series compounds, colloidal silica ispreferably used. The mechanical strength of the hard coat layer ispreferably H or harder, more preferably 2H or harder, and mostpreferably 3H or harder, in terms of pencil grades under 1 Kg of load.On the transparent support, an adhesion layer, a shield layer, aslipping layer and an antistatic layer may be superimposed in additionto the hard coat layer. The shield layer is disposed to shieldelectromagnetic waves and/or infrared radiation.

{Transparent Support}

The anti-reflection film preferably has a transparent support, exceptfor the case where the anti-reflection film is directly placed on a CRTimage displaying surface or a lens surface. As the transparent support,a plastic film is more preferably used than a glass plate (sheet).Examples of materials to form the plastic film include cellulose esters(e.g., triacetyl cellulose, diacetyl cellulose, propionyl cellulose,butyryl cellulose, acetylpropionyl cellulose, and nitro cellulose),polyamides, polycarbonates, polyesters (e.g., polyethyleneterephthalate, polyethylene naphthalate, poly-1,4-cyclohexanedimethyleneterephthalate, polyethylene-1,2-diphenoxyethane-4,4′-dicarboxylate,polybutylene terephthalate), polystyrene (e.g., syndiotacticpolystyrene), polyolefins (e.g., polypropyrene, polyethylene, andpolymethylpentene), polysulfones, polyethersulfones, polyarylates,polyether imides, poly(methyl methacrylate)s, and polyether ketones.Triacetyl cellulose, polycarbonate, polyethylene terephthalate andpolyethylene naphthalate are preferred. The light transmittance of thetransparent support is preferably 80% or more, and more preferably 86%or more. The haze of the transparent support is preferably 2.0% or less,and more preferably 1.0% or less. The refractive index of thetransparent support is preferably in the range of 1.4 to 1.7. Aninfrared-ray absorbing agent or an ultra-violet-ray absorbing agent maybe added to the transparent support. The amount of the infrared-rayabsorbing agent to be added is preferably 0.01 to 20 mass % of thetransparent support, and more preferably 0.05 to 10 mass %. Further, asa lubricant, particles of an inactive inorganic compound may be added tothe transparent support. Examples of such an inorganic compound includeSiO₂, TiO₂, BaSO₄, CaCO₃, talc and kaoline. The transparent support maybe subjected to a surface treatment.

Examples of the surface treatment include a treatment by chemicals, amechanical treatment, a corona discharge treatment, a flame treatment, aUV radiation treatment, a high-frequency treatment, a glow dischargetreatment, an active plasma treatment, a laser treatment, a mixed-acidtreatment, and an ozone-oxidation treatment. Among these examples, aglow discharge treatment, a UV radiation treatment, a corona dischargetreatment and a flame treatment are preferable, and a glow dischargetreatment and a UV radiation treatment are further more preferable.

{Formation of Anti-reflection Film}

In the case where the anti-reflection film is composed of a singlelayer, or multi layers as described above, each layer may be formed bycoating, according to a dip coating process, an air-knife coatingprocess, a curtain coating process, a roller coating process, a wire barcoating process, a gravure coating process, or an extrusion coatingprocess (described in U.S. Pat. No. 2,681,294). Two or more than twolayers may be formed by the simultaneous coating method. The referenceswhich make descriptions of the simultaneous coating method include U.S.Pat. No. 2,761,791, U.S. Pat. No. 2,941,898, U.S. Pat. No. 3,508,947,U.S. Pat. No. 3,526,528 and “Coating Engineering” by Yuji Harasaki, page253, 1973, Asakura Shoten. It is preferable that the reflectance of theanti-reflection film is as low as possible. Specifically, the averagereflectance in the wavelength region of 450 to 650 nm is preferably 2%or less, more preferably 1% or less, and most preferably 0.7% or less.In the case where the anti-reflection film does not have an anti-glarefunction that will be described later, the haze of the anti-reflectionfilm is preferably 3% or less, more preferably 1% or less, and mostpreferably 0.5% or less. The mechanical strength of the anti-reflectionfilm is preferably H or harder, more preferably 2H or harder, and mostpreferably 3H or harder, in terms of pencil grades under 1 Kg of load.The anti-reflection film may have an anti-glare function that enables toscatter external lights. The anti-glare function may be obtained byforming fine irregularities on a surface of the anti-reflection film.When fine particles are used in the low-refractive-index layer,irregularities owing to the fine particles are formed on the surface ofthe anti-reflection film. If the anti-glare function obtained by thefine particles is not enough, a small amount (for example, 0.1 to 50mass %) of relatively large fine particles (for example, particle size:50 nm to 2 μm) may be added to the low-refractive-index layer, thehigh-refractive-index layer, the middle-refractive-index layer, or thehard coat layer. In the case that the anti-reflection film has ananti-glare function, the haze of the anti-reflection film is preferably3 to 30%, more preferably 5 to 20%, and most preferably 7 to 20%. Theanti-reflection film can be used in an image display device such as aliquid crystal display device (LCD), a plasma display panel (PDP), anelectroluminescence display (ELD), and a cathode-ray-tube display device(CRT). The anti-reflection film is disposed so that thehigh-refractive-index layer is placed at the side of the imagedisplaying surface (screen) of an image display device. In the casewhere the anti-reflection film has the transparent support, theanti-reflection film is attached to the image display device so that thetransparent support side of the film is adhered to the image displayingsurface of the image display device. The anti-reflection film may alsobe applied to a case cover, an optical lens, a lens for glasses, awindow shield, a light cover, and a helmet shield.

The anti-reflection film of the present invention is an anti-reflectionfilm of the coating type that is suitable for mass production. Further,the anti-reflection film of the present invention is an anti-reflectionfilm having both excellent durability and resistance to weather, inwhich a surface sliding property can be arbitrarily controlled and alsotransfer of a silicon component to a contact medium is inhibited.Further, the anti-reflection film of the present invention is ananti-reflection film that is low in reflectance and excellent inresistance to abrasion (scratch). Further, the image display device ofthe present invention is an image display device on which reflection isdiminished.

The anti-reflection film of the present invention is high in ananti-reflection performance and excellent in scratch resistance, andmoreover low in possibility of transfer of a silicone component to acontact medium. The polarizing plate and the liquid crystal displaydevice, each of which is provided with the anti-reflection film, havesuch excellent properties that mirroring of external light to be seen onthe display surface is fully prevented from occurring and scratchresistance is high.

Hereinafter, the present invention will be described in more detailbased on the following examples, but the present invention should not belimited thereto.

EXAMPLES

<Synthetic Examples>

Synthesis of Perfluoroolefin Copolymer (P3)

1) Synthesis of M1-(1)

To a mixture of 1H,1H,5H-perfluoropentanol (100 g) and tetra-n-butylammonium hydrogen sulfate (20 g), an aqueous solution of sodiumhydroxide (69 g) dissolved in water (100 ml) was added and stirred atroom temperature for 30 minutes. Further, chloroethyl vinyl ether (183.8g) and toluene (150 ml) were added thereto and heated with stirring at80° C. for 5 hours.

Then, ethyl acetate was added to the resulting reaction solution,followed by washing with water. The organic layer was extracted anddried with magnesium sulfate, and condensed at reduced pressure todistill off the solvents. The resulting liquid was purified by vacuumdistillation, to obtain 100 g of the above-described fluorine-containingvinyl ether (boiling point 73 to 76° C., 1064 Pa).

2) Synthesis of P3

In 100 ml (internal volume) of an autoclave made of stainless steel andprovided with a stirrer, 28 ml of ethyl acetate, 6.0 g of M1-(1), 7.1 gof hydroxyethyl vinyl ether and 0.5 g of dilauroyl peroxide were placed.The interior of autoclave was degassed and substituted with a nitrogengas. Further, 15.0 g of hexafluoro propylene (HFP) was introduced intothe autoclave and heated up to 65° C. The pressure at the time when theinner temperature of the autoclave was elevated to 65° C. was 5.4kg/cm². After stirring for 8 hours to continue the reaction whilekeeping the temperature at 65° C., heating was stopped at the time whenthe pressure was reduced to 3.2 kg/cm², and the inner temperature wasallowed to lower. Then, at the time when the inner temperature loweredto room temperature, remaining unreacted monomers were removed, and thenthe autoclave was opened to take out a reaction solution from there. Thereaction solution was poured into a large excess of hexane, and then asolvent was removed by decantation, to obtain a precipitatedperfluoroolefin copolymer. The resultant perfluoroolefin copolymer wasdissolved in a small amount of ethyl acetate and re-precipitated twicefrom hexane so that the remaining monomers were completely removed.Thereafter, 10 g of the perfluoroolefin copolymer was dissolved in 100ml of ethyl acetate and 2.88 g of triethylamine was added. Then, 2.75 gof acrylic acid chloride was added dropwise while cooling with ice, andthe resulting mixture was stirred for 5 hours. The reaction solution waswashed with water. The organic layer was extracted and thenconcentrated. The thus-obtained perfluoroolefin copolymer wasre-precipitated from hexane, to obtain 6 g of the perfluoroolefincopolymer P3 (Refractive index 1.411).

Other perfluoroolefin copolymers P1, P2, P4 to P25 used in the presentinvention were synthesized in the similar manner as P3.

Synthesis of Compound 1 for Comparison

Synthesis was conducted in the same manner as the aforementioned P3,except that 0.8 g of a silicone macroazo initiator (VPS-1001 (tradename) manufactured by WAKO Pure Chemical Industries, Ltd.) described inJP-A-11-189621 was added for polymerization, to obtain Compound 1 forcomparison having 2 mass % of a silicone block copolymer portionincorporated therein.

Compound 1 for comparison: HFP/M1-(1)/A-1=50/10/40 (molar ratio ofpolymerization unit)/VPS-1001 (2 mass %)

Synthesis of Compound 2 for Comparison

12 g of Compound 2 for comparison was obtained in the same manner asCompound 1 for comparison, except that 10 g of hexafluoropropylene, 4 gof M1-(1), 7 g of A-25, 0.5 g of dilauroyl peroxide and 0.4 g of asilicone macroazo initiator VPS-1001, were mixed in 23 g of ethylacetate, and the resulting mixture was subjected to a polymerizationreaction.

Compound 2 for comparison: HFP/M1-(1)/A-25=50/10/40 (molar ratio ofpolymerization unit)/VPS-1001 (2 mass %)

{Example 1}

(Preparation of a Composition For a Hard Coat Layer)

In a mixed solvent of 943 g of methyl ethyl ketone and 880 g ofcyclohexanon were dissolved 1296 g of trimethylolpropan triacrylate and809 g of a 53.2 mass % solution of poly(glycydyl methacrylate) (massaverage molecular mass: 1.5×10⁴) dissolved in methyl ethyl ketone. Tothe resultant solution were added 48.1 g of Irgacure 184 (trade name)and 24 g of di(t-butyl phenyl iodonium hexafluoro phosphate), understirring. The resultant mixture was stirred for 10 minutes and filteredthrough a filter made of polypropylene having a pore diameter of 0.5 μm,to prepare a composition for a hard coat layer.

(Preparation of Coating Liquid of Low-refractive-index Layer Material)

A mixture of components shown in Table 3 below was dissolved in methylisobutyl ketone. The resulting solution was filtered through apolypropylene filter having a pore size of 1 μm, to prepare a coatingliquid of a low-refractive-index layer.

In Table 3, the colloidal silica refers to MEK-ST (trade name)manufactured by Nissan Chemical Industries Ltd. DPHA (trade name) refersto dipentaerythritolhexaacrylate manufactured by Nippon Kayaku Co., Ltd.DEX 314 (trade name) refers to a trifunctional epoxy hardening agentmanufactured by Nagase Chemicals Ltd. SH200 350 cs (trade name) refersto dimethylsiloxane oil manufactured by Toray Dow Corning Asia Ltd.

UV1 refers to a photo-radical indicator shown below. UV2 refers to alight-induced acid generator shown below. These compounds were eachadded in an amount of 3 mass % based on a solid content.

In table 3, numericals in parentheses { } refer to a mass part of eachcomponent.

TABLE 3 Coating Perfluoroolefin Hardening Colloidal PolysiloxaneHardening liquid copolymer agent silica compound catalyst Ln1 (ThisP1{100} S-(2){2} UV1{3} invention) Ln2 (This P2{100} S-(2){2} UV1{3}invention) Ln3 (This P3{100} S-(2){2} UV1{3} invention) Ln4 (ThisP3{100} S-(3){2} UV1{3} invention) Ln5 (This P3{100} S-(7){2} UV1{3}invention) Ln6 (This P3{100} S-(8){2} UV1{3} invention) Ln7 (This P6{80}DPHA{20} S-(2){2} UV1{3} invention) Ln8 (This P9{100} S-(16){2} UV2{3}invention) Ln9 (This P13{64} DETX{16} MEK-ST{20} S-(16){2} UV2{3}invention) Ln10 (This P13{64} DETX{16} MEK-ST{20} S-(16){5} UV2{3}invention) Ln11 (This P13{64} DETX{16} MEK-ST{20} S-(18){2} UV2{3}invention) Ln12 (This P13{64} DETX{16} MEK-ST{20} S-(20){2} UV2{3}invention) Ln13 (This P13{64} DETX{16} MEK-ST{20} S-(30){2} UV2{3}invention) Ln14 P3{100} UV1{3} (Comparative example) Ln15 P13{64}DETX{16} MEK-ST{20} UV2{3} (Comparative example) Ln16 P3{100} SH200350cs UV1{3} (Comparative {2} example) Ln17 P13{64} DETX{16} MEK-ST{20}SH200 350cs UV2{3} (Comparative {2} example) Ln18 Compound 1 for UV1{3}(Comparative comparison{100} example) Ln19 Compound 2 for UV2{3}(Comparative comparison{100} example)(Preparation of a Titanium Dioxide Dispersion)

30 mass parts of titanium dioxide fine particles having a core/shellstructure (TTO-55B (trade name); shell material, alumina in an amount of9 mass % to the entire particles, manufactured by Ishihara SangyoKaisha, Ltd.), 4.5 mass parts of a commercially available anionicmonomer (PM-21 (trade name), manufactured by Nippon Kayaku Co., Ltd.),0.3 mass part of a commercially available cationic monomer (DMAEA (tradename), manufactured by Kohjin Co., Ltd.), and 65.2 mass parts ofcyclohexanone were dispersed by means of a sand grinder mill, to preparea dispersion of titanium dioxide having a mass-average particle size of53 nm.

(Preparation of a Coating Solution for Middle-refractive-index Layer)

To 49.06 g of the above-mentioned titanium dioxide dispersion, 18.08 gof dipentaerythritol hexaacrylate (DPHA (trade name), manufactured byNippon Kayaku Co., Ltd.), 0.920 g of a photopolymerization initiator(Irgacure 907 (trade name), manufactured by Ciba-Geigy), 0.307 g of aphotosensitizer (Kayacure DETX (trade name), manufactured by NipponKayaku Co., Ltd.), 230.0 g of methyl ethyl ketone, and 500 g ofcyclohexanone were added and stirred. The resulting mixture was filteredthrough a polypropylene filter having a mesh (pure diameter) of 0.4 μm,to prepare a coating solution of a middle-refractive-index layer.

(Preparation of a Coating Solution for High-refractive-index Layer)

To 110.0 g of the above-mentioned titanium dioxide dispersion, 6.29 g ofdipentaerythritol hexaacrylate (DPHA (trade name), manufactured byNippon Kayaku Co., Ltd.), 0.520 g of a photopolymerization initiator(Irgacure 907 (trade name), manufactured by Ciba-Geigy), 0.173 g of aphotosensitizer (Kayacure DETX (trade name), manufactured by NipponKayaku Co., Ltd.), 230.0 g of methyl ethyl ketone and 460.0 g ofcyclohexanone were added and stirred. The resulting mixture was filteredthrough a polypropylene filter having a mesh of 0.4 μm, to prepare acoating solution of a high-refractive-index layer.

(Preparation of an Anti-reflection Film)

The above coating composition for a hard coat layer was applied onto atriacetyl cellulose film (TAC-DU (trade name), manufactured by FujiPhoto Film Co., Ltd.) of thickness 80 μm, using a bar coater, and driedat 80° C. for 2 min. Ultraviolet rays were then irradiated to theresultant coated layer at an irradiation dose of 500 mJ/cm², to cure thecoated layer, while conducting nitrogen purge to make an atmosphere ofan oxygen concentration of 1.0 vol % or less, thereby forming a hardcoat layer of thickness 8 μm.

The above-mentioned coating solution for a middle-refractive-index layerwas coated on the hard coat layer by using a bar coater, and dried at60° C. Thereafter, an ultraviolet ray was irradiated to the coatinglayer to harden the layer. Thus, a middle-refractive-index layer(refractive index: 1.70, thickness: 70 nm, TTB-55B: 21 volume %) wasformed. The above-mentioned coating solution for a high-refractive-indexlayer was coated on the middle-refractive-index layer by using a barcoater, and dried at 60° C. Thereafter, an ultraviolet ray wasirradiated to the coating layer to harden the layer. Thus, ahigh-refractive-index layer (refractive index: 1.95, thickness: 75 nm,TTB-55B: 51 volume %) was formed. The coating solution for alow-refractive-index layer, as shown in the above Table 3 (any one of Ln1 to Ln 13 (the present invention) and Ln 14 to Ln 19 (comparativeexamples)), was coated on the high-refractive-index layer, using a barcoater, so as to become a thickness of 85 nm after hardening. Aftercoating, an ultraviolet ray was irradiated in the atmosphere ofnitrogen, and then the resultant coating layer was heated at 120° C. for10 minutes, to form a low-refractive-index layer. Thus, ananti-reflection film was prepared.

(Evaluation of Anti-reflection Film)

Regarding the thus-obtained films having the 1st layer to 4th layercoated on the support (Ln 1 to Ln 13 (the present invention) and Ln 14to Ln 19 (comparative examples): those having a layer structure as shownin FIG. 1(b)), the following performances were evaluated.

(1) Average Reflectance

A spectral reflectance at an incidence of 5 degrees in the wavelengthregion of 380 nm to 780 nm was measured, by means of a spectrophotometer(manufactured by JASCO Corporation). The thus-obtained results arepresented in terms of an average mirror reflectance in the wavelength of450 nm to 650 nm.

(2) Evaluation of Pencil Hardness

The anti-reflection film was humidified under the conditions of thetemperature 25° C. and the humidity 60% RH for 2 hours. Thereafter,pencil hardness was evaluated according to the evaluation method of thepencil hardness as specified by JIS-K-5400.

(3) Scratch Resistance Test

#0000 steel wool under a loading condition of 200 g/cm² was reciprocated10 time on the surface of the film. A state of scratch occurring at thattime was observed and evaluated, according to the following threegrades:

◯: There was no scratch. Δ: There were observed small scratches. X:There were observed conspicuous scratches.(4) Evaluation of Adhesive Property

A stripping test on the squares of a checkerboard using a Cellotape(registered trademark) was carried out according to JIS-K-5400. Thenumber (x) of measures remaining without being stripped by the tape, per100 of divided measures was mentioned as a ratio of x/100.

(5) Measurement of Dynamic Friction Coefficient

The film sample was humidified in the conditions at 25° C. and arelative humidity of 60% RH for 2 hours, and then subjected tomeasurement by a HEIDON-14 dynamic friction tester using a stainlesssteel ball having a diameter of 5 mmø under a load of 0.98 N at avelocity of 60 cm/min. The thus-measured value was used as a dynamicfriction coefficient.

(6) Test of Transfer of Sliding Component to Contacted Medium

A 80-μm thick triacetyl cellulose film (TD 80UF (trade name)manufactured by Fuji Photo Film Co., Ltd.) and any one of theabove-mentioned samples were attached to each other, and they wereallowed to stand under the loading condition of 2 Kg/m² at 25° C. for 24hours. Thereafter, an amount of Si transferred onto the surface of theabove TAC film base was measured using ESCA. An area ratio of Si/C wasused as a parameter (index). The Si/C value of the base surface beforethe transfer test was 0 (zero).

The results obtained are shown in Table 4.

TABLE 4 Low- Low- refractive- refractive- index index layer layerDynamic coating Refractive Average Pencil Scratch Adhesive frictionTransfer liquid index reflectance hardness resistance propertycoefficient (Si/C) Example (1) Ln1 1.432 0.33 3H ◯ 100/100 0.08 0.000Example (2) Ln2 1.425 0.29 3H ◯ 100/100 0.09 0.001 Example (3) Ln3 1.4220.28 3H ◯ 100/100 0.07 0.002 Example (4) Ln4 1.420 0.27 3H ◯ 100/1000.08 0.001 Example (5) Ln5 1.421 0.27 3H ◯ 100/100 0.09 0.002 Example(6) Ln6 1.422 0.28 3H ◯ 100/100 0.10 0.000 Example (7) Ln7 1.432 0.33 3H◯ 100/100 0.10 0.001 Example (8) Ln8 1.426 0.30 3H ◯ 100/100 0.09 0.001Example (9) Ln9 1.432 0.32 2H ◯ 100/100 0.09 0.002 Example (10) Ln101.431 0.31 3H ◯ 100/100 0.05 0.003 Example (11) Ln11 1.433 0.32 2H ◯100/100 0.07 0.003 Example (12) Ln12 1.432 0.32 2H ◯ 100/100 0.09 0.002Example (13) Ln13 1.434 0.33 2H ◯ 100/100 0.10 0.002 Comparative Ln141.422 0.35 3H Δ  65/100 0.35 0.000 example (1) Comparative Ln15 1.4320.36 2H Δ  45/100 0.38 0.000 example (2) Comparative Ln16 1422 0.34 3H Δ100/100 0.12 0.038 example (3) Comparative Ln17 1.433 0.36 2H Δ 100/1000.12 0.048 example (4) Comparative Ln18 1.424 0.34 3H Δ  90/100 0.140.005 example (5) Comparative Ln19 1.435 0.38 2H Δ  85/100 0.15 0.006example (6)

As is apparent from the results in these examples, it is understood thatthe anti-reflection film of the present invention is very low in surfacereflectance covering over a wide wavelength region, and is tough andsufficiently high in film strength, and is excellent in adhesion to asubstrate. Further, it is understood that a coefficient of kineticfriction of the anti-reflection film of the present invention becomeslower than that of Comparative Examples (3) to (6), even in a similarlevel of addition amount of a polysiloxane component, and theanti-reflection film of the present invention is excellent in scratchresistance. Further, as shown in the results of Example (10), it isunderstood that increase in an addition amount of a sliding agentconsiderably lowers a coefficient of kinetic friction, and an amount ofa silicone component transferred to a contact medium also becomes low.Further, it is understood that the anti-reflection film of the presentinvention is excellent in leveling property of the film surface,resulting in a low reflectance.

{Preparation of a Display Device Equipped with the Anti-reflection Film}

Any one of the anti-reflection films prepared in the above Examples (1)to (13) and Comparative examples (1) to (6) was provided on a displaysurface of a liquid crystal display of a personal computer PC9821NS/340W (trade name) available from Nippon Electric Co., Ltd. Thus,surface display samples were prepared. The level of mirroring abackground view on the surface of these produced samples owing to asurface reflection was evaluated by examination with the naked eye.There was almost no mirroring of a background view on the displaydevices equipped with the anti-reflection films prepared in Examples (1)to (13) according to the present invention, so that the display imagewas easily observed. Further, these display devices according to thepresent invention had a sufficient surface mechanical strength. Incontrast, even though the display devices equipped with theanti-reflection films prepared in Comparative examples (1) to (6)reduced mirroring of a background view thereon, their surface mechanicalstrength was poor.

Having described our invention as related to the present embodiments, itis our intention that the invention not be limited by any of the detailsof the description, unless otherwise specified, but rather be construedbroadly within its spirit and scope as set out in the accompanyingclaims.

1. An anti-reflection film, comprising a low-refractive-index layerformed by hardening a composition, said composition containing apolysiloxane compound having a reactive organic functional group whichcontributes to a crosslinking reaction, represented by formula 1, and aperfluoroolefin copolymer represented by formula 2, wherein the massratio of the polysiloxane compound to the perfluoroolefin copolymer isfrom 0.05:100 to 20:100:

wherein, in formula 1, R¹, R², R³ and R⁴ each represent a substituenthaving 1 to 20 carbon atoms; when there are a plurality of any of R¹,R², R³ or R⁴, R¹s, R²s, R³s or R⁴s each are the same or different fromeach other; at least one of R¹, R³ and R⁴ represents the reactiveorganic functional group; x is an integer that is within the range of1≦x≦4; y is an integer that is within the range of 10≦y≦500; z is aninteger that is within the range of 0≦z≦500; and said polysiloxanecompound may be a random copolymer or a block copolymer;

wherein, in formula 2, Rf¹ represents a perfluoroalkyl group having 1 to5 carbon atoms; Rf² represents a fluorine-containing alkyl group having1 to 30 carbon atoms, said fluorine-containing alkyl group having astraight chain, branched chain, or alicyclic structure; A represents acomponent having at least one reactive organic functional group whichcontributes to a crosslinking reaction; B represents an optionalcomponent; a, b, c and d each represent a mole fraction (%) of eachcomponent, in which a, b, c and d satisfy the following conditions;5≦a≦70, 5≦b≦90, 5≦c≦95, 0≦d≦90.
 2. The anti-reflection film according toclaim 1, wherein the perfluoroolefin copolymer described in claim 1 hasa group having a reactive partial structure which is the same as thereactive organic functional group incorporated in the polysiloxanecompound.
 3. The anti-reflection film according to claim 1, wherein thelow-refractive-index layer is applied as a liquid composition coatingwhich further comprises a hardening agent.
 4. The anti-reflection filmaccording to claim 3, wherein the perfluoroolefin copolymer or thehardening agent described in claim 3 has a group having a reactivepartial structure which is the same as the reactive organic functionalgroup incorporated in the polysiloxane compound.
 5. The anti-reflectionfilm according to claim 1, wherein the reactive organic functional groupdescribed in claim 1 is a ring-opening polymerizable group or a radicalpolymerizable group.
 6. The anti-reflection film according to claim 5,wherein the reactive organic functional group described in claim 5 is anepoxy group, an oxetanyl group, or a (meth)acryloyl group.
 7. Theanti-reflection film according to claim 1, wherein the component A ofthe perfluoroolefin copolymer has at least one of a (meth)acryloylgroup, an epoxy group or an oxetanyl group.
 8. The anti-reflection filmaccording to claim 1, wherein the composition for thelow-refractive-index layer is applied as a liquid composition coatingwhich further contains fine silica particles having an average particlesize of 5 to 50 nm.
 9. The anti-reflection film according to claim 1,which has a high-refractive-index layer containing inorganic fineparticles, provided between the low-refractive-index layer described inclaim 1 and a support.
 10. An anti-reflection film, having theanti-reflection film according to claim 1, on a transparent support. 11.An image display device, comprising the anti-reflection film accordingto claim 10.